With admittedly close to zero sailing experience, I would think that if your boat (no matter how big or "tiny") is getting "considerable" water onboard, you have bigger problems than your canned food.
It doesn't make sense to me either that the size of the vessel has much to do with how watertight it is.
But like I said, I don't have much experience in this!
Water comes over the sides/top in choppy seas. It rains on the deck, and the cabin has a door. It's normal. Bigger boats have taller sides. That's the difference with size, which waves will spray you. Keeping things dry is a challenge.
With admittedly close to zero sailing experience, I would think that if your boat (no matter how big or "tiny") is getting "considerable" water onboard, you have bigger problems than your canned food.
It doesn't make sense to me either that the size of the vessel has much to do with how watertight it is.
But like I said, I don't have much experience in this!